client/cmd/rpc: RPC CLI

client/cmd/rpc/main.go

Index: client/cmd/rpc/main.go
diff --git a/client/cmd/rpc/main.go b/client/cmd/rpc/main.go
new file mode 100644
index 0000000000000000000000000000000000000000..39282d1563ddd8f8eaf359f6654e7d833b185a17
--- /dev/null
+++ b/client/cmd/rpc/main.go
@@ -0,0 +1,110 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"strings"
+
+	"github.com/maruel/subcommands"
+	gol "github.com/op/go-logging"
+	"golang.org/x/net/context"
+
+	"github.com/luci/luci-go/common/logging/gologger"
+)
+
+const (
+	userAgent = "luci-rpc"
+)
+
+// cmdRun is a base of all rpc subcommands.
+// It defines some common flags, such as logging, and useful methods.
+type cmdRun struct {
+	subcommands.CommandRunBase
+	verbose bool
+}
+
+// registerBaseFlags registers common flags used by all subcommands.
+func (r *cmdRun) registerBaseFlags() {
+	r.Flags.BoolVar(&r.verbose, "verbose", false, "Enable more logging.")
+}
+
+// initContext creates a context with installed logger.
+func (r *cmdRun) initContext() context.Context {
+	// Setup logger.
+	loggerConfig := gologger.LoggerConfig{
+		Format: `%{message}`,
+		Out:    os.Stderr,
+		Level:  gol.WARNING,
+	}
+	if r.verbose {
+		loggerConfig.Level = gol.DEBUG
+	}
+	return loggerConfig.Use(context.Background())
+}
+
+// argErr prints an err and usage to stderr and returns an exit code.
+func (r *cmdRun) argErr(format string, a ...interface{}) int {
+	if format != "" {
+		fmt.Fprintf(os.Stderr, format+"\n", a...)
+	}
+	fmt.Fprintln(os.Stderr, cmdCall.ShortDesc)
+	fmt.Fprintln(os.Stderr, cmdCall.UsageLine)
+	fmt.Fprintln(os.Stderr, "\nFlags:")
+	r.Flags.PrintDefaults()
+	return 1
+}
+
+// done prints err to stderr if it is not nil and returns an exit code.
+func (r *cmdRun) done(err error) int {
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return 2
+	}
+	return 0
+}
+
+var application = &subcommands.DefaultApplication{
+	Name:  "rpc",
+	Title: "Remote Procedure Call CLI",
+	Commands: []*subcommands.Command{
+		cmdCall,
+		cmdShow,
+	},
+}
+
+func main() {
+	os.Exit(subcommands.Run(application, os.Args[1:]))
+}
+
+// parseServer validates and parses a server URL.
+func parseServer(server string) (*url.URL, error) {
+	switch {
+	case strings.HasPrefix(server, ":"):
+		server = "http://localhost" + server
+	case !strings.HasPrefix(server, "http://") && !strings.HasPrefix(server, "https://"):
+		return nil, fmt.Errorf("server must start with http:// or https://, unless it is :port")
+	}
+
+	u, err := url.Parse(server)
+	u.Path = strings.TrimSuffix(u.Path, "/")
+	switch {
+	case err != nil:
+		return nil, err
+	// Double-check scheme.
+	case u.Scheme != "http" && u.Scheme != "https":
+		return nil, fmt.Errorf("invalid scheme %q. Must be http or https", u.Scheme)
+	case u.Path != "":
+		return nil, fmt.Errorf("must not have path")
+	case u.RawQuery != "":
+		return nil, fmt.Errorf("must not have query")
+	case u.Fragment != "":
+		return nil, fmt.Errorf("must not have fragment")
+	default:
+		return u, nil
+	}
+}